1. Field of the Invention
This invention relates to improvements in apparatus wherein two images, obtained by imaging an identical field of view on an object to-be-observed in directions different from each other, are presented to the left eye and the right eye of an observer, thereby to make the stereoscopic observation of the object to-be-observed possible. More particularly, it relates to a system for appointing positions on the images in such stereoscopic image observing apparatus.
As objects to which this invention is applicable, there can be mentioned, for example, stereoscopic image observing apparatus in various television systems such as industrial television; stereoscopic image observing apparatus in physical and chemical appliances such as scanning electron microscope, transmission type electron microscope, X-ray micro analyzer and ion microprobe analyzer; and stereoscopic image observing apparatus in medical diagnostic appliances such as X-ray photograph equipment and ultrasonic imaging equipment.
2. Description of the Prior Art
The stereoscopic image observing apparatus according to this invention presents two images individually to the left eye and the right eye of an observer, the two images being obtained by imaging an identical field of view on an object to-be-observed in directions different from each other, and thereby makes the stereoscopic observation of the object to-be-observed possible.
In such stereoscopic image observing apparatus, it is sometimes necessary to measure the three-dimensional distance between any desired two points in a stereoscopic image. To this end, it is necessary to make definite those positions on two plane images to which any desired one point in the stereoscopic image corresponds.
In order to measure the three-dimensional distance between any desired two points in a stereoscopic image, an apparatus has been developed wherein marks are respectively indicated at two positions on two plane images as correspond to the two points and wherein the three-dimensional distance between the two points in the stereoscopic image is calculated from the two-dimensional distance between the two marks on each of the plane images, as described in U.S. Pat. No. 4,039,829 entitled "Stereoscopic Measuring Apparatus," issued Aug. 2, 1977.
In order to appoint by the marking any desired one point in the stereoscopic image formed of the two plane images, it is required to put a pair of marks into the corresponding positions on both the plane images in such a manner that one mark lies at one position. Moreover, the pair of marks need be moved to the respective positions on both the plane images (left eye image and right eye image) as correspond to the desired one point in the stereoscopic image.
The prior-art apparatus has been so constructed that, for the location of the pair of marks, the movement of the mark on the left eye image and the movement of the mark on the right eye image are carried out quite independently. It has therefore involved the disadvantages that the locating operation is troublesome and that the construction of the apparatus is complicated.